Japanese Patent Application Publication No. 2011-244682 (Patent Document 1) describes a technique for, in a vehicle that is able to execute control for charging an in-vehicle battery with electric power from an outside of the vehicle (hereinafter, referred to as “external charging”) or execute control for discharging electric power from the in-vehicle battery to the outside of the vehicle (hereinafter, referred to as “external discharging”), automatically carrying out external charging or external discharging in accordance with an operation mode of the vehicle and an electricity price. Specifically, in the case where the operation mode of the vehicle is a first mode, the vehicle described in Patent Document 1 automatically carries out external charging when the electricity price is lower than a charge reference price. On the other hand, in the case where the operation mode of the vehicle is a second mode in which the vehicle is not operated for a while, the vehicle described in Patent Document 1 automatically carries out external charging when an actual electricity price is lower than a discharge reference price, and automatically carries out external discharging when the electricity price is higher than the discharge reference price.